Methods and apparatuses for plmn rate control

ABSTRACT

Methods and apparatuses are disclosed for public land mobile network (PLMN) rate control. According to an embodiment, a network function determines whether a value of PLMN rate control applicable to a terminal device has been changed. When determining that the value of PLMN rate control has been changed, the network function sends the changed value of PLMN rate control to the terminal device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/437,299, filed on Sep. 8, 2021, which is the 35 U.S.C. § 371 NationalStage of International Patent Application No. PCT/CN2020/078569, filedMar. 10, 2020, which claims priority to: 1) International PatentApplication No. PCT/CN2019/082512, filed Apr. 12, 2019 and 2)International Patent Application No. PCT/CN2019/077651, filed Mar. 11,2019. The above identified applications are incorporated by thisreference.

TECHNICAL FIELD

Embodiments of the disclosure generally relate to communication, and,more particularly, to methods and apparatuses for public land mobilenetwork (PLMN) rate control.

BACKGROUND

This section introduces aspects that may facilitate better understandingof the present disclosure. Accordingly, the statements of this sectionare to be read in this light and are not to be understood as admissionsabout what is in the prior art or what is not in the prior art.

Serving PLMN rate control is intended to protect the control plane (CP)from excessive CP data. As such, the operator may define a rate that isused throughout at the PLMN level. For example, the Serving PLMN ratecontrol value may be defined by a mobility management entity (MME) orsession management entity (SMF) and expressed as “x non-access stratum(NAS) data protocol data units (PDUs) per deci hour”. There may be aseparate limit for uplink and downlink NAS data PDUs.

A user equipment (UE) shall limit the rate at which it generates uplinkNAS data PDUs to comply with the serving PLMN policy. Serving PLMN ratecontrol may be provided by the network to the UE in ACTIVATE DEFAULT EPSBEARER CONTEXT REQUEST message or PDU SESSION ESTABLISHMENT RESPONSE.The term EPS refers to evolved packet system. The indicated rate isvalid until the packet data network (PDN) connection or the PDU sessionis released.

A PDN gateway (GW), a service capability exposure function (SCEF), auser plane function (UPF) or a network exposure function (NEF) shalllimit the rate at which it generates downlink data PDUs. Serving PLMNrate control may be provided by an MME to the GW/SCEF in CREATE SESSIONREQUEST, MODIFY BEARER REQUEST, FORWARD RELOCATION REQUEST, CONTEXTRESPONSE message.

SUMMARY

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

One of the objects of the disclosure is to provide an improved solutionfor PLMN rate control.

According to a first aspect of the disclosure, there is provided amethod performed by a network function. The method may comprisedetermining whether a value of PLMN rate control applicable to aterminal device has been changed. The method may further comprise, whendetermining that the value of PLMN rate control has been changed,sending the changed value of PLMN rate control to the terminal device.

In this way, the network function can be enabled to provide the latestPLMN rate control value to a terminal device.

In an embodiment of the disclosure, whether the value of PLMN ratecontrol has been changed may be determined in response to a request fortracking area update (TAU) from the terminal device.

In an embodiment of the disclosure, the changed value of PLMN ratecontrol may be sent in a reply for accepting TAU.

In an embodiment of the disclosure, the reply for accepting TAU may be aTAU Accept message or a Registration Accept message.

In an embodiment of the disclosure, the changed value of PLMN ratecontrol may be sent in a Downlink non-access stratum (NAS) Transportmessage.

In an embodiment of the disclosure, the Downlink NAS Transport messagemay be a request for modifying a connection between the terminal deviceand a gateway node.

In an embodiment of the disclosure, the request for modifying aconnection between the terminal device and a gateway node may be aModify evolved packet system (EPS) Bearer Context Request message or aprotocol data unit (PDU) Session Modification Command message.

In an embodiment of the disclosure, determining that the value of PLMNrate control has been changed may comprise one of: determining that theterminal device has moved from a first PLMN to a second PLMN and valuesof PLMN rate control are differently configured in the network functionfor the first and second PLMNs; determining that the terminal device hasmoved from a first PLMN to a second PLMN and a value of PLMN ratecontrol configured in the network function for the second PLMN isdifferent from that configured in previous network function for thefirst PLMN; determining that the terminal device remains in a same PLMNand a value of PLMN rate control configured in the network function forthe same PLMN has been changed; and determining that the terminal deviceremains in a same PLMN and a value of PLMN rate control configured inthe network function for the same PLMN is different from that configuredin previous network function for the same PLMN.

According to a second aspect of the disclosure, there is provided amethod performed by a terminal device. The method may comprisereceiving, from a network function, a changed value of PLMN rate controlapplicable to the terminal device. The method may further comprise usingthe changed value of PLMN rate control for a connection between theterminal device and a gateway node.

In this way, the terminal device can be enabled to use the latest PLMNrate control value.

In an embodiment of the disclosure, the method may further comprisesending a request for TAU to the network function. The changed value ofPLMN rate control may be received in response to the sending of therequest for TAU.

In an embodiment of the disclosure, the changed value of PLMN ratecontrol may be received in a reply for accepting TAU.

In an embodiment of the disclosure, the reply for accepting TAU may be aTAU Accept message or a Registration Accept message.

In an embodiment of the disclosure, the changed value of PLMN ratecontrol may be received in a Downlink NAS Transport message.

In an embodiment of the disclosure, the Downlink NAS Transport messagemay be a request for modifying the connection between the terminaldevice and the gateway node.

In an embodiment of the disclosure, the request for modifying theconnection between the terminal device and the gateway node may be aModify EPS Bearer Context Request message or a PDU Session ModificationCommand message.

According to a third aspect of the disclosure, there is provided anetwork node. The network node may comprise at least one processor andat least one memory. The at least one memory may contain instructionsexecutable by the at least one processor, whereby the network node maybe operative to determine whether a value of PLMN rate controlapplicable to a terminal device has been changed. The network node maybe further operative to, when determining that the value of PLMN ratecontrol has been changed, send the changed value of PLMN rate control tothe terminal device.

In an embodiment of the disclosure, the network node may be operative toperform the method according to the above first aspect.

According to a fourth aspect of the disclosure, there is provided aterminal device. The terminal device may comprise at least one processorand at least one memory. The at least one memory may containinstructions executable by the at least one processor, whereby theterminal device may be operative to receive, from a network function, achanged value of PLMN rate control applicable to the terminal device.The terminal device may be further operative to use the changed value ofPLMN rate control for a connection between the terminal device and agateway node.

In an embodiment of the disclosure, the terminal device may be operativeto perform the method according to the above second aspect.

According to a fifth aspect of the disclosure, there is provided acomputer program product. The computer program product may compriseinstructions which when executed by at least one processor, cause the atleast one processor to perform the method according to any of the abovefirst and second aspects.

According to a sixth aspect of the disclosure, there is provided acomputer readable storage medium. The computer readable storage mediummay comprise instructions which when executed by at least one processor,cause the at least one processor to perform the method according to anyof the above first and second aspects.

According to a seventh aspect of the disclosure, there is provided anetwork node. The network node may comprise a determination module fordetermining whether a value of PLMN rate control applicable to aterminal device has been changed. The network node may further comprisea sending module for, when determining that the value of PLMN ratecontrol has been changed, sending the changed value of PLMN rate controlto the terminal device.

According to an eighth aspect of the disclosure, there is provided aterminal device. The terminal device may comprise a reception module forreceiving, from a network function, a changed value of PLMN rate controlapplicable to the terminal device. The terminal device may furthercomprise a control module for using the changed value of PLMN ratecontrol for a connection between the terminal device and a gateway node.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, features and advantages of the disclosure willbecome apparent from the following detailed description of illustrativeembodiments thereof, which are to be read in connection with theaccompanying drawings.

FIG. 1 is a diagram showing an exemplary communication system into whichan embodiment of the disclosure is applicable;

FIG. 2 is a flowchart illustrating a method performed by a networkfunction according to an embodiment of the disclosure;

FIG. 3 is a flowchart illustrating a method performed by a terminaldevice according to an embodiment of the disclosure;

FIG. 4 is a flowchart illustrating an exemplary process according to anembodiment of the disclosure;

FIG. 5 is a flowchart illustrating an exemplary process according toanother embodiment of the disclosure;

FIG. 6 is a block diagram showing an apparatus suitable for use inpracticing some embodiments of the disclosure;

FIG. 7 is a block diagram showing a network node according to anembodiment of the disclosure; and

FIG. 8 is a block diagram showing a terminal device according to anembodiment of the disclosure.

DETAILED DESCRIPTION

For the purpose of explanation, details are set forth in the followingdescription in order to provide a thorough understanding of theembodiments disclosed. It is apparent, however, to those skilled in theart that the embodiments may be implemented without these specificdetails or with an equivalent arrangement.

Serving PLMN rate control could be changed due to configuration changeor UE location change. MME can include the changed value to GW throughMODIFY BEARE REQUEST or CREATE SESSION REQUEST but cannot inform UEabout the change because this information element (IE) is only includedin ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST message. That means afterthe bearer is activated, this IE cannot be changed towards UE until thebearer is deactivated.

For example, UE attaches to MME in PLMN 1 and activates one CP-only PDNconnection. The Serving PLMN rate control for PLMN 1 is sent to UE andSGW. Then UE moves to another location in PLMN 2 which has a differentserving PLMN rate control value. In tracking area update (TAU)procedure, MME informs SGW about the new value of PLMN 2 in MODIFYBEARER REQUEST or CREATE SESSION REQUEST message. But the new valuecannot be sent to UE. This will lead to inconsistency between GW, MMEand UE.

Furthermore, Serving PLMN rate control should be PLMN level control forthe UE. Although Serving PLMN rate control IE is defined as a PDN levelcontrol in ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST, CREATE SESSIONREQUEST, MODIFY BEARER REQUEST messages, it is defined as a UE levelcontrol in FORWARD

RELOCATION REQUEST, CONTEXT RESPONSE messages. Thus, there exists a kindof misalignment in 3rd generation partnership project (3GPP).

The present disclosure proposes an improved solution for PLMN ratecontrol. The basic idea is to enable a network function (e.g. an MME, anSMF, etc.) to inform a terminal device when there is a change of servingPLMN rate control value. Hereinafter, the solution will be described indetail with reference to FIGS. 1-8 .

As used herein, the term “communication system” refers to a systemfollowing any suitable communication standards, such as the firstgeneration (1G), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G communicationprotocols, and/or any other protocols either currently known or to bedeveloped in the future. Furthermore, the communications between aterminal device and a network function in the communication system maybe performed according to any suitable generation communicationprotocols, including, but not limited to, 1G, 2G, 2.5G, 2.75G, 3G, 4G,4.5G, 5G communication protocols, and/or any other protocols eithercurrently known or to be developed in the future.

In the following, different terms may refer to a same or similar networkfunction or network node with the same or similar functionality indifferent communication systems. Thus, the specific terms used herein donot limit the present disclosure only to the communication systemrelated to the specific terms, which however can be more generallyapplied to other communication systems.

FIG. 1 is a diagram showing an exemplary communication system into whichan embodiment of the disclosure is applicable. As shown, thecommunication system comprises a terminal device 110, a radio accessnetwork (RAN) 120, a mobility management entity (MME) 130, a servinggateway (SGW) 140, a packet data network (PDN) gateway (PGW) 150 and ahome subscriber server (HSS) 160. Note that the number of each entitymentioned above may be more than one.

The terminal device 110 can communicate through a radio accesscommunication link with the RAN 120. The communication may be performedaccording to any suitable communication protocols. The terminal devicemay also be referred to as, for example, user equipment (UE), mobilestation, mobile unit, subscriber station, access terminal, or the like.It may refer to any end device that can access a wireless communicationnetwork and receive services therefrom. By way of example and notlimitation, the terminal device may include a portable computer, animage capture terminal device such as a digital camera, a gamingterminal device, a music storage and playback appliance, a mobile phone,a cellular phone, a smart phone, a tablet, a wearable device, a personaldigital assistant (PDA), or the like.

In an Internet of things (IoT) scenario, a terminal device may representa machine or other device that performs monitoring and/or measurements,and transmits the results of such monitoring and/or measurements toanother terminal device and/or a network equipment. In this case, theterminal device may be a machine-to-machine (M2M) device, which may, ina 3GPP context, be referred to as a machine-type communication (MTC)device. Particular examples of such machines or devices may includesensors, metering devices such as power meters, industrial machineries,bikes, vehicles, or home or personal appliances, e.g. refrigerators,televisions, personal wearables such as watches, and so on.

The RAN 120 may include, for example, a universal mobiletelecommunications system (UMTS) terrestrial RAN (UTRAN), a globalsystem for mobile communication (GSM)/enhanced data rate for GSMevolution (EDGE) RAN (GERAN), and/or an evolved universal terrestrialRAN (E-UTRAN). The UTRAN and the GERAN can each include radio networkcontroller (RNC) nodes to control communications through radio basestations providing radio access communication links to terminal devicesthat are within their respective communication service cells. TheE-UTRAN can include radio base station nodes (eNodeBs or eNBs) that canprovide the combined functionality of the RNC nodes and base stations ofthe UTRAN and the GERAN.

The MME 130 is a core network function in evolved packet system (EPS)and can carry out mobility management of the terminal device 110, bearermanagement, and the like. The SGW 140 can route and forward signallingand user data packets, while also acting as the mobility anchor for userplane during inter-base station/eNodeB handovers and as the anchor formobility between long term evolution (LTE) and other 3GPP technologies.The PGW 150 can provide entry and exit points to a packet-based networkfor the traffic of the terminal device 110 flowing through the SGW 140.The packet-based network may include the Internet and/or other packetnetwork elements. The HSS 160 is a control-plane function in the corenetwork of 3GPP public land mobile network (PLMN) and can managesubscriber information of the terminal device 110.

It should be noted that the MME 130, the SGW 140 and the HSS 160 aremerely exemplary examples of the components in the communication systemand may be replaced by components with similar functionalities. Forexample, in 5G core (5GC), the MME may be replaced (in some aspects) bya session management function (SMF), and the HSS may be replaced by aunified data management (UDM).

FIG. 2 is a flowchart illustrating a method performed by a networkfunction according to an embodiment of the disclosure. For example, thenetwork function may be an MME, an SMF, or any other entity havingsimilar functionality. The network function may be implemented either asa network element on a dedicated hardware, as a software instancerunning on a dedicated hardware, or as a virtualized functioninstantiated on an appropriate platform, e.g. on a cloud infrastructure.At block 202, the network function determines whether a value of PLMNrate control applicable to a terminal device has been changed. As afirst option, the determination at block 202 may be performed inresponse to a request for tracking area update (TAU) from the terminaldevice. For this first option, a result that the value of PLMN ratecontrol has been changed may be determined if any one of the followingfour scenarios is detected. As the first scenario, the terminal devicehas moved from a first PLMN to a second PLMN and values of PLMN ratecontrol are differently configured in the network function for the firstand second PLMNs. In this first scenario, the terminal device is servedby the same network function when the terminal device moves from thefirst PLMN to the second PLMN.

As the second scenario, the terminal device has moved from a first PLMNto a second PLMN and a value of PLMN rate control configured in thenetwork function for the second PLMN is different from that configuredin previous network function for the first PLMN. In this secondscenario, before and after moving from the first PLMN to the secondPLMN, the terminal device is served by the previous network function andthe network function respectively. For example, the second scenario maybe similar to inter-MME TAU in LTE.

As the third scenario, the terminal device remains in a same PLMN and avalue of PLMN rate control configured in the network function for thesame PLMN has been changed. For example, such change of the configuredPLMN rate control value may be triggered locally or from another networkfunction, e.g. another network function (NF) in 5G. In this thirdscenario, the terminal device is served by the same network functionbefore and after the trigger event that triggers the request for TAUfrom the terminal device. Furthermore, although the change of the PLMNrate control value is due to the configuration change of the networkfunction, the request for TAU from the terminal device is used as thetrigger event that triggers the determination of block 202.

As the fourth scenario, the terminal device remains in a same PLMN and avalue of PLMN rate control configured in the network function for thesame PLMN is different from that configured in previous network functionfor the same PLMN. In this fourth scenario, before and after the triggerevent that triggers the request for TAU from the terminal device, theterminal device is served by the previous network function and thenetwork function respectively. For example, the fourth scenario may besimilar to inter-MME TAU in LTE. Furthermore, the request for TAU fromthe terminal device is used as the trigger event that triggers thedetermination of block 202.

As a second option, there is no need for the determination at block 202to be performed in response to a request for TAU. For example, the abovethird scenario may also be applicable to the second option. Once theconfiguration change of the network function is detected, it may bedetermined that the value of PLMN rate control has been changed.

At block 204, when determining that the value of PLMN rate control hasbeen changed, the network function sends the changed value of PLMN ratecontrol to the terminal device. In this way, the network function can beenabled to provide the latest PLMN rate control value to a terminaldevice. In the above first option, the changed value of PLMN ratecontrol may be sent in a reply for accepting TAU. As an exemplaryexample, the reply for accepting TAU may be a TAU Accept message in LTEor a Registration Accept message in 5G. Alternatively, the changed valueof PLMN rate control may be sent in a Downlink NAS Transport message.For instance, the Downlink NAS Transport message may be a request formodifying a connection between the terminal device and a gateway node.The gateway node may be an SGW, a user plane function (UPF), or anyother entity having similar functionality. The connection may be a PDNconnection in LTE or a PDU session in 5G. As an exemplary example, therequest for modifying a connection between the terminal device and agateway node may be a Modify EPS Bearer Context Request message in LTEor a PDU Session Modification Command message in 5G.

In the above second option, the changed value of PLMN rate control maybe sent in a Downlink NAS Transport message. For example, once theconfiguration change of the network function is detected as describedabove, the changed value of PLMN rate control may be sent to everyterminal device served by the network function.

FIG. 3 is a flowchart illustrating a method implemented at a terminaldevice according to an embodiment of the disclosure. At block 302, theterminal device receives, from a network function, a changed value ofPLMN rate control applicable to the terminal device. For example, asdescribed above with respect to the second option for block 202, theterminal device may remain in a same PLMN and a value of PLMN ratecontrol configured in the network function for the same PLMN may havebeen changed. This may lead to the reception at block 302. For example,the changed value of PLMN rate control may be received in a Downlink NASTransport message.

Optionally, at block 301, the terminal device sends a request for TAU tothe network function. The changed value of PLMN rate control may bereceived at block 302 in response to the sending of the request for TAU.For example, as described above with respect to the first option forblock 202, there may be four scenarios. As the first scenario, theterminal device has moved from a first PLMN to a second PLMN and valuesof PLMN rate control are differently configured in the network functionfor the first and second PLMNs. As the second scenario, the terminaldevice has moved from a first PLMN to a second PLMN and a value of PLMNrate control configured in the network function for the second PLMN isdifferent from that configured in previous network function for thefirst PLMN. As the third scenario, the terminal device remains in a samePLMN and a value of PLMN rate control configured in the network functionfor the same PLMN has been changed. As the fourth scenario, the terminaldevice remains in a same PLMN and a value of PLMN rate controlconfigured in the network function for the same PLMN is different fromthat configured in previous network function for the same PLMN. Forexample, in any one of the above four scenarios, the changed value ofPLMN rate control may be received in a reply for accepting TAU or in aDownlink NAS Transport message.

At block 304, the terminal device uses the changed value of PLMN ratecontrol for a connection between the terminal device and a gateway node.The connection and the gateway node have been explained above. In thisway, the changed value may be used for the subsequent PLMN rate controlon the connection. In the above first option, the changed value may beused at the terminal device level. In the above second option, thechanged value may be used at the connection level.

FIG. 4 is a flowchart illustrating an exemplary process according to anembodiment of the disclosure. As shown, the exemplary process involvesfive entities, i.e. a UE, an eNB, an MME, an HSS and a GW (e.g. SGW).This process enables the MME to inform the UE with the change of servingPLMN rate control in UE level. At block 401, the UE attaches to the MMEin PLMN 1 and establishes a PDN connection which uses S 11-U. The S 11-Uis an interface used for small data transmissions between the MME andthe SGW. Since the serving PLMN rate control is applicable to controlplane (CP), the PDN connection is set to CP only. The MME informs the UEand the GW of ServingPlmnRateControl for PLMN 1. At block 402, the UEmoves to a new location in PLMN 2. Suppose the UE is served by the sameMME during this process and ServingPlmnRateControl for PLMN 2 isdifferent from PLMN 1 in the MME's local configuration.

At block 403, the UE sends a TAU Request to the MME. Since the servingPLMN rate control is applicable to CP, the TAU Request has a signalingactive flag. At block 404, the MME detects that ServingPlmnRateControlfor PLMN 2 is different from PLMN 1, and thus sends a Modify BearerRequest to the SGW with new ServingPlmnRateControl. At block 405, theSGW replies with a Modify Bearer Response. At block 406, the MME sends aTAU Accept to the UE with the new ServingPlmnRateControl. With thisnewly added information element (IE) (ServingPlmnRateControl in TAUAccept), the MME can inform the UE of the latest value ofServingPlmnRateControl such that the UE can limit uplink NAS data PDUsaccording to the network policy timely. It can also keep the consistencybetween the UE, the MME and the GW. The UE may save this new value. Atblock 407, the UE replies with a TAU Complete. Since the new value isprovided via TAU Accept, the UE needs to apply it for each bearer (atthe UE level).

FIG. 5 is a flowchart illustrating an exemplary process according to anembodiment of the disclosure. Similar to FIG. 4 , this process alsoinvolves five entities, i.e. a UE, an eNB, an MME, an HSS and a GW (e.g.SGW). The process enables the MME to inform the UE with the change ofserving PLMN rate control in PDN level. Blocks 501-505 in this processare the same as blocks 401-405 of FIG. 4 and their details are omittedhere. At block 506, the MME sends a TAU Accept to the UE. At block 507,the UE replies with a TAU Complete. At block 508, the MME sends a ModifyEPS Bearer Context Request with new ServingPlmnRateControl to the UE,which is included in a Downlink NAS Transport message. The NAS procedureModify EPS Bearer Context Request/Accept is legacy message in 3GPP. TheServingPlmnRateControl is a newly added IE in Modify EPS Bearer ContextRequest. At block 509, the UE replies with a Modify EPS Bearer ContextAccept. The UE may update the ServingPlmnRateControl locally. With thenewly added blocks 508-509, the UE can be informed of the changedServingPlmnRateControl value such that the UE can limit uplink NAS dataPDUs according to the network policy timely. It can also keep theconsistency between the UE, the MME and the GW. It should be noted thattwo blocks shown in succession in the figures may, in fact, be executedsubstantially concurrently, or the blocks may sometimes be executed inthe reverse order, depending upon the functionality involved.

FIG. 6 is a block diagram showing an apparatus suitable for use inpracticing some embodiments of the disclosure. For example, any one ofthe network function and the terminal device described above may beimplemented through the apparatus 600. As shown, the apparatus 600 mayinclude a processor 610, a memory 620 that stores a program, andoptionally a communication interface 630 for communicating data withother external devices through wired and/or wireless communication.

The program includes program instructions that, when executed by theprocessor 610, enable the apparatus 600 to operate in accordance withthe embodiments of the present disclosure, as discussed above. That is,the embodiments of the present disclosure may be implemented at least inpart by computer software executable by the processor 610, or byhardware, or by a combination of software and hardware.

The memory 620 may be of any type suitable to the local technicalenvironment and may be implemented using any suitable data storagetechnology, such as semiconductor based memory devices, flash memories,magnetic memory devices and systems, optical memory devices and systems,fixed memories and removable memories. The processor 610 may be of anytype suitable to the local technical environment, and may include one ormore of general purpose computers, special purpose computers,microprocessors, digital signal processors (DSPs) and processors basedon multi-core processor architectures, as non-limiting examples.

FIG. 7 is a block diagram showing a network node according to anembodiment of the disclosure. As shown, the network node 700 comprises adetermination module 702 and a sending module 704. The determinationmodule 702 may be configured to determine whether a value of PLMN ratecontrol applicable to a terminal device has been changed, as describedabove with respect to block 202. The sending module 704 may beconfigured to, when determining that the value of PLMN rate control hasbeen changed, send the changed value of PLMN rate control to theterminal device, as described above with respect to block 204.

FIG. 8 is a block diagram showing a terminal device according to anembodiment of the disclosure. As shown, the terminal device 800comprises a reception module 802 and a control module 804. The receptionmodule 802 may be configured to receive, from a network function, achanged value of PLMN rate control applicable to the terminal device, asdescribed above with respect to block 302. The control module 804 may beconfigured to use the changed value of PLMN rate control for aconnection between the terminal device and a gateway node, as describedabove with respect to block 304. The modules described above may beimplemented by hardware, or software, or a combination of both.

In general, the various exemplary embodiments may be implemented inhardware or special purpose circuits, software, logic or any combinationthereof. For example, some aspects may be implemented in hardware, whileother aspects may be implemented in firmware or software which may beexecuted by a controller, microprocessor or other computing device,although the disclosure is not limited thereto. While various aspects ofthe exemplary embodiments of this disclosure may be illustrated anddescribed as block diagrams, flow charts, or using some other pictorialrepresentation, it is well understood that these blocks, apparatus,systems, techniques or methods described herein may be implemented in,as non-limiting examples, hardware, software, firmware, special purposecircuits or logic, general purpose hardware or controller or othercomputing devices, or some combination thereof.

As such, it should be appreciated that at least some aspects of theexemplary embodiments of the disclosure may be practiced in variouscomponents such as integrated circuit chips and modules. It should thusbe appreciated that the exemplary embodiments of this disclosure may berealized in an apparatus that is embodied as an integrated circuit,where the integrated circuit may comprise circuitry (as well as possiblyfirmware) for embodying at least one or more of a data processor, adigital signal processor, baseband circuitry and radio frequencycircuitry that are configurable so as to operate in accordance with theexemplary embodiments of this disclosure.

It should be appreciated that at least some aspects of the exemplaryembodiments of the disclosure may be embodied in computer-executableinstructions, such as in one or more program modules, executed by one ormore computers or other devices. Generally, program modules includeroutines, programs, objects, components, data structures, etc. thatperform particular tasks or implement particular abstract data typeswhen executed by a processor in a computer or other device. The computerexecutable instructions may be stored on a computer readable medium suchas a hard disk, optical disk, removable storage media, solid statememory, RAM, etc. As will be appreciated by one of skill in the art, thefunction of the program modules may be combined or distributed asdesired in various embodiments. In addition, the function may beembodied in whole or in part in firmware or hardware equivalents such asintegrated circuits, field programmable gate arrays (FPGA), and thelike.

References in the present disclosure to “one embodiment”, “anembodiment” and so on, indicate that the embodiment described mayinclude a particular feature, structure, or characteristic, but it isnot necessary that every embodiment includes the particular feature,structure, or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it is submitted that it is within the knowledge of oneskilled in the art to implement such feature, structure, orcharacteristic in connection with other embodiments whether or notexplicitly described.

It should be understood that, although the terms “first”, “second” andso on may be used herein to describe various elements, these elementsshould not be limited by these terms. These terms are only used todistinguish one element from another. For example, a first element couldbe termed a second element, and similarly, a second element could betermed a first element, without departing from the scope of thedisclosure. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed terms.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to limit the present disclosure. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”,“comprising”, “has”, “having”, “includes” and/or “including”, when usedherein, specify the presence of stated features, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, elements, components and/or combinations thereof. Theterms “connect”, “connects”, “connecting” and/or “connected” used hereincover the direct and/or indirect connection between two elements.

The present disclosure includes any novel feature or combination offeatures disclosed herein either explicitly or any generalizationthereof. Various modifications and adaptations to the foregoingexemplary embodiments of this disclosure may become apparent to thoseskilled in the relevant arts in view of the foregoing description, whenread in conjunction with the accompanying drawings. However, any and allmodifications will still fall within the scope of the non-Limiting andexemplary embodiments of this disclosure.

1. A method performed by a network function comprising: determiningwhether a value of public land mobile network (PLMN) rate control hasbeen changed; and as a result of determining that the value of PLMN ratecontrol has been changed, sending the changed value of PLMN rate controlto a terminal device, wherein the changed value of PLMN rate control isused by the terminal device as a maximum allowed limit of uplink controlplane user data for a Protocol Data Unit (PDU) session.
 2. The method ofclaim 1, wherein whether the value of PLMN rate control has been changedis determined in response to a request for tracking area update (TAU)from the terminal device.
 3. The method of claim 2, wherein the changedvalue of PLMN rate control is sent in a reply for accepting TAU.
 4. Themethod of claim 1, wherein the changed value of PLMN rate control issent in a downlink non-access stratum (NAS) Transport message, thedownlink NAS Transport message is a request for modifying a connectionbetween the terminal device and a gateway node, and the request formodifying a connection between the terminal device and a gateway node isa Modify evolved packet system Bearer Context Request message.
 5. Themethod of claim 1, wherein determining that the value of PLMN ratecontrol has been changed comprises one of: determining that the terminaldevice has moved from a first PLMN to a second PLMN and values of PLMNrate control are differently configured in the network function for thefirst and second PLMNs; determining that the terminal device has movedfrom a first PLMN to a second PLMN and a value of PLMN rate controlconfigured in the network function for the second PLMN is different fromthat configured in previous network function for the first PLMN;determining that the terminal device remains in a same PLMN and a valueof PLMN rate control configured in the network function for the samePLMN has been changed; or determining that the terminal device remainsin a same PLMN and a value of PLMN rate control configured in thenetwork function for the same PLMN is different from that configured inprevious network function for the same PLMN.
 6. A method performed by aterminal device, the method comprising: receiving, from a networkfunction, a changed value of public land mobile network (PLMN) ratecontrol; and using the changed value of PLMN rate control as a maximumallowed limit of uplink control plane user data for a Protocol Data Unit(PDU) session.
 7. The method of claim 6, further comprising: sending arequest for tracking area update (TAU) to the network function, whereinthe changed value of PLMN rate control is received in response to thesending of the request for TAU.
 8. The method of claim 7, wherein thechanged value of PLMN rate control is received in a reply for acceptingTAU.
 9. The method of claim 6, wherein the changed value of PLMN ratecontrol is received in a Downlink non-access stratum (NAS) Transportmessage, the downlink NAS Transport message is a request for modifyingthe connection between the terminal device and the gateway node, and therequest for modifying the connection between the terminal device and thegateway node is a Modify evolved packet system Bearer Context Requestmessage.
 10. The method of claim 6, wherein the network function is amobility management entity.
 11. A network node comprising: at least oneprocessor; and at least one memory, the at least one memory containinginstructions executable by the at least one processor, wherein thenetwork node is operative to: determine whether a value of public landmobile network (PLMN) rate control has been changed; and as a result ofdetermining that the value of PLMN rate control has been changed, sendthe changed value of PLMN rate control to the to a terminal device. 12.A terminal device comprising: at least one processor; and at least onememory, the at least one memory containing instructions executable bythe at least one processor, whereby the terminal device is operative to:receive, from a network function, a changed value of public land mobilenetwork (PLMN) rate control; and use the changed value of PLMN ratecontrol as a maximum allowed limit of uplink control plane user data fora Protocol Data Unit (PDU) session.
 13. The terminal device of claim 12,further configured to send a request for tracking area update (TAU) tothe network function, wherein the changed value of PLMN rate control isreceived in response to the sending of the request for TAU.
 14. Theterminal device of claim 13, wherein the changed value of PLMN ratecontrol is received in a reply for accepting the TAU request.
 15. Theterminal device of claim 12, wherein the network function is a sessionmanagement function (SMF), and the changed value of PLMN rate control isreceived in a PDU SESSION MODIFICATION COMMAND message.
 16. The methodof claim 1, wherein the network function is a Session ManagementFunction (SMF), and the changed value of PLMN rate control is sent tothe terminal device in a PDU SESSION MODIFICATION COMMAND message. 17.The method of claim 6, wherein the network function is a sessionmanagement function (SMF), and the changed value of PLMN rate control isreceived in a PDU SESSION MODIFICATION COMMAND message.
 18. The networknode of claim 11, wherein the network node is configured to determinewhether the value of PLMN rate control has been changed in response to arequest for tracking area update (TAU) from the terminal device.
 19. Thenetwork node of claim 18, wherein the changed value of PLMN rate controlis sent in a reply for accepting TAU.
 20. The network node of claim 11,wherein the changed value of PLMN rate control is sent in a downlinknon-access stratum (NAS) Transport message, the downlink NAS Transportmessage is a request for modifying a connection between the terminaldevice and a gateway node, and the request for modifying the connectionbetween the terminal device and a gateway node is a Modify evolvedpacket system Bearer Context Request message.